module Rake::FileUtilsExt

def rake_check_options(options, *optdecl)

options are found.
+optdecl+. An ArgumentError exception is thrown if non-declared
Check that the options do not contain options not listed in 
def rake_check_options(options, *optdecl)
  h = options.dup
  optdecl.each do |name|
    h.delete name
  end
  raise ArgumentError, "no such option: #{h.keys.join(' ')}" unless
    h.empty?
end